In many modern communication systems, a directional antenna from a mobile station aimed directly at a base station provides the highest quality signal, which directly relates to the data rate which can be achieved. The antenna gives the wireless system three fundamental properties: gain (measure of an increase in power, typically expressed as dB), direction (the shape of the transmission pattern), and polarization. As the gain of a directional antenna increases the angle of radiation usually decreases. This can provide greater coverage distance, but with a reduced coverage angle. The changes in gain, direction and polarization also impact the strength of the signal. Because directional antennas focus RF energy in a particular direction, as the gain of a directional antenna increases, the coverage distance increases but the effective coverage angle decreases.
To point a directional antenna in the absence of prior knowledge of the location/direction of the other end of the radio link requires using a measuring receiver circuit to measure incident signal strength from the desired transmitter. By using active power control, software on the cellular base station attempts to ensure that all the incoming signals from the mobile stations are at approximately the same strength. This is achieved by the base station measuring each received signal and implementing a control loop that sends power control instructions to the mobile station to transmit more or less power. This control loop is updated continuously during a connection
A key impediment to achieving an optimal signal for maximum data rate is that there is no direct way to determine the position of the base station relative to the mobile station and hence an optimal alignment of the directional antenna for achieving optimal signal quality and highest data throughput. Instructions to the mobile station to transmit more or less power may not achieve an optimal received signal. What is needed is a system and device for exploiting an existing mechanism of modern wireless communication systems which observes a current signal strength and can then reorient the direction antenna, noting the inferred signal strength at each successive orientation, until a satisfactory signal strength is achieved.